This invention relates generally to radio systems and more particularly to an oscillator which adjusts its output frequency to match the frequency of an input signal.
In an electronic warfare environment, it is often desirable to have an apparatus that can transmit a signal at the same frequency as a received signal. One example of such an apparatus is a jammer. The jammer receives signals from an adversary's radar and then transmits a very strong signal at the same frequency. The strong signal disrupts the operation of the radar.
For a jammer, or other similar apparatus, to operate effectively, it must contain an oscillator that produces a signal at the same frequency as the input signal. Such an oscillator is called a "set-on oscillator" because its output frequency is "set-on" the input frequency.
In most applications, it is important that the set-on oscillator set-on the input frequency quickly. In some applications, the input signal is a short pulse such that the oscillator must set-on the input signal during the pulse. Additionally, it would be desirable for the set-on oscillator to be accurate and to be constructed relatively inexpensively.